The operation of internal combustion engines can be optimized by the metered introduction of water into the air/fuel mixture to be burnt. This has basically been known for many decades, and corresponding exemplary embodiments can be found, inter alia, in aircraft from the Second World War or in Oldsmobile passenger cars from the early 60's. In more recent times, economic trials have confirmed the potential of water injection also for direct-injection spark-ignition engines.
In spark-ignition engines, the introduction of water suppresses, in particular, the knocking of the engine. As a result, in particular in charged engines, the power of the engine can be increased and/or its efficiency increased. In spark-ignition engines, the introduction of water into the intake region of the internal combustion engine provides virtually all the advantages available from water injection. In diesel engines, by introducing water into the charge, it is possible, in particular, to reduce the emissions of soot and/or NOx. However, in diesel engines, a more costly direct injection of water into the combustion chamber, separate from the fuel or emulsified with the fuel, is often necessary to achieve all the potential available from water injection.
Hitherto, despite the known advantages, systems for introducing water into the internal combustion engine have not become commonplace in mass production of passenger cars. Reasons for this are, for example, the additional costs, additional mass, and the required installation space for equipping a passenger car with a system for introducing water into the internal combustion engine. The requirements made of customers to provide a further operating medium in the form of a sufficient water supply can also adversely affect customer satisfaction and therefore the economic success of a vehicle manufacturer trying to put onto the market vehicles with systems for introducing water into the engine. However, various systems for introducing water into the internal combustion engine have been described.
U.S. Pat. No. 4,503,813A describes an arrangement for condensing water from the exhaust gas in order to make available water for introduction into the intake section. A description is given of, inter alia, arranging the condensation device above a reservoir container so that the condensed water flows into the reservoir container under gravity.
US20040103859A1 describes an arrangement for introducing water into the intake section. In this arrangement, a water reservoir container is arranged above a water injection nozzle so that the water can flow into the injection nozzle under gravity.
WO2004025108A1 describes a device for introducing liquid additive (cerium salt) into the intake region of a diesel engine.
U.S. Pat. No. 8,375,899B2 describes a fuel system in which, in addition to fuel, water is also introduced into the engine. The water is condensed from the exhaust gas section or the vehicle air-conditioning system and is collected in a separated-off part of the fuel tank. The collected water is introduced into the internal combustion engine by direct injection.
US20110168128A1 describes a system which condenses water from the exhaust gas in an internal combustion engine and feeds it to the engine by direction injection. It is mentioned that depending on the fuel the water can be mixed with the fuel and fed together with it to the engine.
DE102007050511A1 describes a method for precipitating water out of a vehicle air-conditioning system in order to introduce it into an internal combustion engine.
U.S. Pat. No. 8,820,270B2 describes an arrangement for injecting water into the intake region of an internal combustion engine, and a device for precipitating the water from the exhaust gas of the internal combustion engine.
U.S. Pat. No. 4,279,223A describes a device and an arrangement for precipitating water from the exhaust gas of an internal combustion engine. The precipitated water is then fed to a modified vaporizer and in this way finally to the internal combustion engine.
EP2657473A2 describes a device for recovering water from the exhaust gas in an internal combustion engine or from an air-conditioning system. The recovered water is made available to the internal combustion engine using a pump.
US20110138793A1 describes a device for condensing and precipitating water from the exhaust gas of an internal combustion engine. The collected water is fed to the fuel inlet of the internal combustion engine using a pump and is mixed at said inlet with the fuel.
Furthermore, the risk of the water supply freezing requires structural precautions. The previously proposed systems, such as an electric heater, also require further equipment complexity, increased costs, and entail further disadvantages, such as discharging of the vehicle battery or increased fuel consumption for the generation of the required electricity.
U.S. Pat. No. 8,286,615 describes an intake manifold with integral water-cooled charge-air cooler. U.S. Pat. No. 6,619,274 describes a cooled inlet system for outboard motors in V arrangement, wherein the cooled inlet system is arranged in the V of the engine. JPH06123225A also describes a cooled inlet system for an outboard motor. The article “HPA Motorsports 3.2 VR6 Performance Upgrades” describes an intake bridge with integrated charge-air cooler.
However, the inventors herein have recognized potential issues with such systems. As one example, an arrangement for introducing water into the intake region of an internal combustion engine with little structural complexity that prevents the water from being frozen when it is requested for delivery into the inlet region of an internal combustion engine has not been known.
In one example, the issues described above may be addressed by a system comprising: an internal combustion engine having an intake manifold; a throttle valve arranged between an intake manifold inlet and the internal combustion engine; a water inlet connected to the intake manifold downstream of the throttle valve and having a Venturi nozzle which is coupled to a lower region of a first water container positioned above the water inlet; a bypass valve positioned between the intake manifold inlet and the water inlet; and a control mechanism connected to the bypass valve to open it dependent on engine load, causing a pressure drop at the Venturi nozzle that forces water into the intake manifold. In this way, an arrangement for introducing water into the intake region of an internal combustion engine that is cost-effective to manufacture and requires a small installation space is made available. Further, by introducing the water through a Venturi nozzle, a higher water flow and more atomization may be achieved than would be achieved by relying only on gravity feed. Further still, atomized water may enter the combustion chambers directly from the intake manifold and evaporate within the combustion chambers, causing cooling. In some prior approaches, water was injected on the backside of a hot intake valve (port injection) and latent heat of vaporization was lost as some portion of the water evaporated on the intake valve instead of in the combustion chamber. In addition, a pump, pressure lines, and an injector for each combustion chamber were required to inject the water. In other approaches, an injector was placed within each combustion chamber. Such approaches required high pressure pumps, high pressure lines, and an injector in each combustion chamber.
As one example, the first water container may be connected heat-conductively to the intake manifold and may form an integral inlet component. In this way, heat may be transmitted from air flowing through the intake manifold may be transferred to the water in the first water container to prevent the water from being frozen when it is requested for delivery into the intake region of the internal combustion engine. Further, a controller may control actuation of the bypass valve so that water is delivered under select engine operating conditions and not under others. In this way, the arrangement provides for the delivery of water to the intake region of the internal combustion engine in a pumpless manner and without an additional heating element.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.